You probably should check that it's not a false alarm, 14.8V is really high. You should be fast charging the battery at around 14.4V, nominally floating about 13.9V~14.1V. For a constant current charger you'd consider them fully charge when they reach 2.45V/cell, which is 14.7V, and that's when you would start to fold back unless you were trying to equalize the battery. Equalization is something you don't want to do often as it shortens the life of the cells and even then for a sealed battery you would not want to exceed 2.5V/cell (15V) ever.